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Implementation:Datajuicer Data juicer Load Formatter

From Leeroopedia
Knowledge Sources
Domains Data_Loading, Formatting
Last Updated 2026-02-14 16:00 GMT

Overview

Concrete tool for automatic format detection and formatter selection provided by Data-Juicer.

Description

load_formatter is a factory function that automatically selects and instantiates the most appropriate formatter based on the file extensions found at the given dataset path. It scans the dataset path for files, groups them by extension using find_files_with_suffix, then scores each registered formatter in the FORMATTERS registry by how many matching files its SUFFIXES cover. The formatter with the highest match count is selected, instantiated with the intersecting suffixes, and returned. This is the auto-detection entry point for the format system.

Usage

Use when you want Data-Juicer to automatically detect and load datasets without manually specifying the file format, such as in the DefaultLocalDataLoadStrategy and other high-level callers.

Code Reference

Source Location

Signature

def load_formatter(
    dataset_path,
    text_keys=None,
    suffixes=None,
    add_suffix=False,
    **kwargs
) -> BaseFormatter:

Import

from data_juicer.format.load import load_formatter

I/O Contract

Inputs

Name Type Required Description
dataset_path str Yes Path to a dataset file or directory to auto-detect format from
text_keys List[str] No Key names of fields that store sample text. Default: None
suffixes list No File suffixes to filter by. Default: None (auto-detect all)
add_suffix bool No Whether to add file suffix to dataset meta info. Default: False
**kwargs Any No Extra arguments passed to the selected formatter

Outputs

Name Type Description
formatter BaseFormatter An instantiated formatter matching the detected file format (e.g. JsonFormatter, CsvFormatter)

Usage Examples

from data_juicer.format.load import load_formatter

# Auto-detect format and load
formatter = load_formatter(
    dataset_path="/path/to/dataset/",
    text_keys=["text"]
)
dataset = formatter.load_dataset(num_proc=4)

# Auto-detect with suffix filtering
formatter = load_formatter(
    dataset_path="/path/to/mixed_data/",
    suffixes=[".json", ".jsonl"]
)
dataset = formatter.load_dataset()

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